Here are some nice keystrokes that work in Debian, and probably other distros as well as these are essentially Gnome actions:

• PrintScreen -- Takes a screenshot of your entire desktop and saves it to the Desktop folder
• Alt + PrintScreen -- Saves a screenshot of the focused window to the Desktop Folder
• Shift + PrintScreen -- Lets you select an area of the screen, and saves to the Desktop Folder
• Ctrl + PrintScreen -- Takes a screenshot of your entire desktop and copies it to the clipboard
• Ctrl + Alt + PrintScreen -- copies a screenshot of the focused window to the clipboard
• Ctrl + Shift + PrintScreen -- Lets you select an area of the screen, and copies it to the clipboard
• Ctrl + Shift + Alt + R -- Records a Screencast) of your entire desktop and saves it to your Videos folder

The 'Desktop' folder may be different on other flavours, like 'Pictures' on Fedora.

The commands which allow selection of an area are not much use when you can't see but the others are nice. I particularly like the idea of a screen-cast.

Thanks to the guys on the Surrey Linux User Group email list for these.